This study is designed to evaluate the ability of 2 drugs, Co-enzyme Q10 and remacemide, to slow the progression of Huntington+s disease. The latter is an incurable neurologic disease causing progressive dementia, involuntary movements, incoordination, and behavioral problems. Co-enzyme Q10, remacemide, and placebos are given in a blinded manner. Participants are evaluated by clinical examinations. The progression of Huntington+s disease, as assessed by clinical evaluations, will be compared in drug and placebo treated groups. If successful, this will be the first successful intervention in a common degenerative neurologic disease.